Oily industrial waste waters can seriously disturb biological drainage processes. The emulsified oil particles hamper normal aerobic biological purification in settling installations as the oil film on the water surface prevents the absorption of atmospheric oxygen.
Therefore, wash waters from such industrial installations as oil and gasoline separators, paper and carpet factories, barrel washing plants, factories for the degreasing of machine parts, and plants using coolant emulsions for machining operations must be purified to meet government standards as to allowable percentages of mineral oils.
One type of purification process with which the apparatus of the instant invention is concerned involves chemical separation. Such a process, to be low cost, uses demulsifying products and chemically reacting adsorbents to achieve an adsorption of the separating reagent as well as an extremely high, fine distribution of the substances to be eliminated. Adsorbed dirt particles and oily organic substances become firmly bound and finely distributed in a resulting sludge cake. These adsorbed dirt particles are not dissolved by normal mechanical treatments so that their reemergence under normal environmental conditions is virtually excluded.
The process for purification by chemical separation includes collecting the oily waste waters, adding a demulsifier if the oil content exceeds 2% and separating, or draining, the oil which floats to the surface. A powdered separating reagent may be mixed into the emulsion with adsorption occurring in a very short period of time.
Another object of this invention is to provide an improved purification apparatus that can be transported to the site where contaminated emulsions, solutions, industrial waste waters or the like occur.
The performance of prior waste water treatment and sludge removal apparatus have been hampered by the amount of "down-time" consumed while the treatment chamber of the apparatus was filled with the waste water to be treated. It was also discovered that sludge drained from a treatment chamber did not normally have sufficient time to dry.
Thus, a further object of this invention is to increase overall performance in waste water treatment by providing in an apparatus two treatment chambers, such that one may operate while the second is being filled, and by also providing that sludge produced by the apparatus is provided with an elongated drying path.
Another object is to provide an apparatus for handling waste taken from a solution by a continuous napped, or fleece-like, filter band of a disposable character such as a paper-like band.